Often, in building construction, there must be an interface between a wall and a glass window or door. This interface can either be in interior construction, such as the entrance to an office, or a divider wall, or exterior, such as the front entrance to an office or store.
Typically, the glass window is mounted within a mullion which has a deep groove to receive the edge of the glass. This mullion is typically attached directly to the wall structure, usually a stud. The stud can be wood or metal. In such an installation, additional work must be undertaken to trim and caulk the mating edges of the mullion and wall. The installation is time-consuming and expensive. A need exists for a more efficient and less costly system. This is particularly true for interior construction as interior office walls are often changed each time a new lessee takes over an office space.